If I make a speech at an event, and a TD happens to be in the audience, am I lobbying?

It is the content, not the method of communication that determines whether it should be recorded as a lobbying activity. Generally a communication, such as a speech, that is aimed at a general audience and does not target Designated Public Officials would not be considered lobbying. However, if a speech is made specifically to one or more DPOs, or they are directly addressed in the course of the speech, it may be lobbying depending on whether the subject of the speech concerns a relevant matter and whether the person making the speech falls within the scope of the Act.

It may also be useful to consider whether other communications occurring during the event would be relevant communications as defined in section 5(4) of the Regulation of Lobbying Act.